CN103077806A - Self-excited push-pull type converter - Google Patents
Self-excited push-pull type converter Download PDFInfo
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Abstract
The invention discloses a self-excited push-pull type converter. More than two magnetic cores are combined into a whole to realize magnetic saturation which is same with that of an integral magnetic core so as to realize the conversion of a push-pull triode. The self-excited push-pull type converter is realized by the method that mirror surfaces are used as the contact surfaces of the magnetic cores, and a magnetic solution is added at the connecting part of the mirror surfaces or the magnetic cores are baked at a high temperature to realize the magnetic saturation. The self-excited push-pull type converter has high conversion efficiency, excellent consistency and high reliability. Meanwhile, an obtained transformer has the characteristics of small size and simple winding technology.
Description
Technical field
The present invention relates to Switching Power Supply, particularly self-excited push-pull type transducer class Switching Power Supply.
Background technology
Existing self-excited push-pull type transducer, circuit structure is also made the Royer circuit from the self-oscillation push-pull transistor single phase transformer DC converter of nineteen fifty-five U.S. Luo Ye (G.H.Royer) invention, and this also is the beginning of realizing the high frequency conversion control circuit; Partial circuit from nineteen fifty-seven U.S.'s auto-excitation type of looking into match (Jen Sen, some places translations " well is gloomy ") invention recommend the dual transformer circuit, after be called as self-oscillation Jensen circuit or Jensen circuit; These two kinds of circuit, the descendant is referred to as self-excited push-pull type transducer.The related work principle of self-excited push-pull type transducer has description in " principle of Switching Power Supply and the design " the 67th page to 70 pages of Electronic Industry Press, this book ISBN 7-121-00211-6.The principal mode of circuit is above-mentioned famous Royer circuit and self-oscillation Jensen circuit.
Shown in Fig. 1 is the common application of self-excited push-pull type transducer, and circuit structure is the Royer circuit; Circuit shown in Fig. 2 is exactly famous self-oscillation Jensen circuit, Chinese Chang Yinyi is " well is gloomy " circuit, in Fig. 1 and Fig. 2, circuit all will utilize the magnetic core saturation characteristic of transformer B1 to vibrate, in the Jensen of Fig. 2 circuit, the self-oscillating frequency of circuit and driving function change by magnetically saturated transformer B1 and realize, therefore, main power transformer B2 can be operated in undersaturated condition.
The frequency of oscillation of Royer circuit is the function of supply voltage, and " principle of Switching Power Supply and design " the 68th page of the 18th row in the Electronic Industry Press has description, this book ISBN 7-121-00211-6.Here quote as follows:
In the formula: f is frequency of oscillation;
BWFor work magnetic flux density (T), generally get 50%～70% saturation point
B m Value; N is coil turn;
SBe the magnetic core net sectional area;
VsBe working power voltage.
Can find out that from formula (1) under the certain prerequisite of the operating voltage of Royer circuit, its operating frequency is very stable.In order conveniently to understand the operation principle of Royer circuit, utilize the magnetic core saturation characteristic to carry out the push-pull oscillator this point thereby further understand the application, particularly circuit, here take Fig. 1 as example, its operation principle is described.
The circuit structure of Fig. 1 is: input filter capacitor C is connected between voltage input end and the ground, and input voltage is carried out filtering; Filtered input voltage access start-up circuit, start-up circuit is composed in parallel by biasing resistor R1 and capacitor C 1; The two ends of biasing resistor R1 are connected with voltage input end and for two push-pull transistor TR1, TR2 base stage provide the transformer B1 primary coil NB1 of positive feedback to be connected centre cap with NB2 respectively; The emitter of two push-pull transistor TR1, TR2 altogether, two collector electrodes are distinguished two terminations of connection transformer primary coil NP1 and NP2, two terminations of base stage connection transformer primary coil NB1 and NB2, the centre cap that primary coil NP1 is connected with NP2 connects voltage input end; The secondary coil NS of transformer B1 connects output circuit to voltage output end.
Its operation principle summary is: referring to Fig. 1, plugged moment, biasing resistor R1 and capacitor C 1 shunt circuit are the base stage of triode TR1 and TR2 by coil NB1 and NB2 winding, emitter provides forward bias, two triode TR1 and TR2 begin conducting, because two dynatron performances can not be just the same, therefore, wherein first conducting of triode meeting, suppose the conducting of triode TR2 elder generation, produce collector current IC2, the voltage of the coil NP2 winding that it is corresponding is upper just lower negative, according to the Same Name of Ends relation, just lower negative induced voltage also appears in its base winding NB2 winding, and this voltage has increased the base current of triode TR2, this is the process of a positive feedback, thereby makes very soon triode TR2 saturation conduction; Correspondingly, the voltage of the coil NB1 winding that triode TR1 is corresponding is upper just lower negative, and this voltage has reduced the base current of triode TR1, the very fast fully cut-off of triode TR1.
Electric current in coil NP2 winding corresponding to triode TR2, and the magnetic flux density that produces of this electric current is in time and linear increasing, but magnetic flux density is increased to the saturation point B that approaches or reach transformer B1 magnetic core
mThe time, the inductance value of coil NP2 reduces rapidly, thereby the collector current of triode TR2 is sharply increased, the speed that increases is much larger than the increase of base current, triode TR2 breaks away from saturated, and the collector electrode of triode TR2 increases to the pressure drop UCE of emitter, correspondingly, voltage on the transformer NP2 winding just reduces same numerical value, the voltage of coil NB2 winding induction reduces, and the result also reduces triode TR2 base voltage, causes triode TR2 to change to the cut-off direction, at this moment, voltage on the transformer B1 coil will oppositely, make another triode TR1 conducting, after this, repeat this process, form push-pull oscillator.The waveform of the output of winding Ns as shown in Figure 3.
Fig. 4 is the square magnetic hysteresis loop of transformer B1 magnetic core, wherein+and B
m,-B
mFor two saturation point of magnetic core, in the half period of Fig. 3, the route of the working point of transformer B1 magnetic core motion is ABCDE, and moving line is EFGHA in lower half period.In fact, electric current in coil windings corresponding to triode TR2 or TR1, and the magnetic flux density that produces of this electric current is in time and linearity when being increased among Fig. 4 D point or H point, circuit will be recommended conversion, be the conducting of another triode, and corresponding triode can end.Because there is a memory time (storage time) in triode, be that transistor base receives cut-off signals, short time just begins decline until shutoff and collector current will be delayed time, can be created among Fig. 4 memory time, magnetic core working point moving line is mobile from the D point to the E point, accordingly, or magnetic core working point moving line mobile from the H point to the A point.
Analog structure shown in Fig. 2 is exactly the circuit that switch drive function and main power transformer break away from, as shown in Figure 2.Preamble was described, and the self-oscillating frequency of circuit and driving function change by magnetically saturated transformer B1 and realize, therefore, main power transformer B2 can be operated in undersaturated condition.Although magnetic saturation appears in B1, because the volume less of B1, the energy that magnetic saturation consumes is little, and under the same conditions, the overall efficiency of Jensen circuit is slightly high.
Above-mentioned Royer, Jensen electric circuit characteristic are: utilize the magnetic core saturation characteristic to carry out push-pull oscillator, the transformer output waveform is approximate square wave, and the conversion efficiency of circuit is higher.Magnetic core will be at specific time instant near saturation condition, so can't adopt the magnetic core that has air gap.Above-mentioned self-excited push-pull type transducer is essential to use the magnetic saturation type magnetic core, and magnetic core to add air gap be known anti-magnetically saturated means.
In the self-excited push-pull type transducer, existing is not to utilize the magnetic core saturation characteristic to carry out the circuit of push-pull oscillator yet, such as collector mode of resonance Royer circuit, it is output as sine wave or near sinusoidal ripple, collector mode of resonance Royer circuit claims again " cold cathode fluorescent lamp inverter (CCFL inverter) ", also can be referred to as CCFL inverter or CCFL converter, the CCFL converter seals in ten times of inductance more than the inductance value of main power winding at current supply circuit, and recommend between the transistor collector resonant capacitance that capacity is very large in parallel at two, to obtain sine wave output or near sinusoidal ripple.
Another kind does not utilize the magnetic core saturation characteristic to carry out the self-excited push-pull type transducer of push-pull oscillator, nineteen ninety publishes in the People's Telecon Publishing House, the 57th page to 70 pages of " power conversion technology " that Wang Guiying writes have description, and this book is for ISBN number 7-115-04229-2/TN353.The 3rd section second row (the third line on Fig. 2-28) of 57 page of the 3rd joint mentioned in this book: transformer is operated in unsaturated state, and the volume ratio of transformer is larger.
The solid line of " air gap is arranged " indication among Fig. 5 is the magnetic hysteresis loop after very little air gap left by magnetic core corresponding to Fig. 4; The dotted line of " without the air gap " indication among Fig. 5 is for the magnetic hysteresis loop of contrast usefulness, and is identical with Fig. 4.Known technology is thought, opened after the air gap, coercive force and saturation point are constant, but reach anxious poly-increase of the required H value of saturation point, be the electric current increase in the coil, this needs thicker enamelled wire come coiling transformer B1, otherwise original enamelled wire can't bear larger electric current, so, the cost of transformer B1 and volume all can increase; Reach anxious poly-increase of the required H value of saturation point, another method is that the coil institute coiling number of turn of transformer B1 is multiplied, and same, the number of turn is multiplied, and brings internal resistance to increase, and loss increases, the decrease in efficiency of self-excited push-pull type transducer.This also is above-mentioned, and " power conversion technology " " transformer is operated in unsaturated state, and the volume ratio of transformer is larger " of mentioning produces reason.
Self-excited push-pull type transducer is in present field of switch power, because in small-signal model, unique ac small signal input impedance is positive power supply, and the ac small signal input impedance of other Switching Power Supply is for negative, it is extremely inconvenient when ac small signal input impedance is used for negative switch power parallel, the ac small signal input impedance of self-excited push-pull type transducer is being for just, and is in parallel, cascade is extremely easy to use, so be used widely.
For convenient, utilize the magnetic core saturation characteristic to carry out the self-excited push-pull type transducer of push-pull oscillator, hereinafter referred to as the saturation type self-excited push-pull type transducer, the circuit that does not utilize the magnetic core saturation characteristic to carry out push-pull oscillator is called unsaturation formula self-excited push-pull type transducer.Saturation type self-excited push-pull type transducer operating frequency is more stable, and volume of transformer is little; The volume ratio of unsaturation formula self-excited push-pull type transducer transformer is larger, and frequency alters a great deal with the variation of load factor.Saturation type self-excited push-pull type transducer and unsaturation formula self-excited push-pull type transducer there is no significant difference at circuit form, namely can't distinguish this two kinds of converters at schematic diagram, and its main distinction is exactly on the magnetic core of transformer.
There is following shortcoming in above-mentioned self-excited push-pull type transducer:
1, the transformer winding of saturation type self-excited push-pull type transducer difficulty
Referring to Fig. 1, Fig. 2, comprise Royer circuit and Jensen circuit, transformer B1 in the circuit utilizes the magnetic core saturation characteristic to carry out push-pull oscillator, in order to realize magnetic saturation, all be the magnetic core coiling transformer B1 that adopts without air gap, the coiling of general employing magnet ring, 2011, whole world industrial circle newly promotes in 7,000 ten thousand self-excited push-pull type transducer micropower power supply modules, all adopt the magnet ring coiling transformer of magnetic circuit closure, and the diameter major part is less than 10mm, Fig. 6 schematic diagram has provided the structure of this magnet ring, because magnetic circuit is closed, enamelled wire all will pass the middle hole of magnet ring during coiling, and coiling is difficulty relatively.Transformer B1 must utilize magnetic saturation to realize pushing off conversion among Fig. 1 and Fig. 2, can not open air gap, this brings very large difficulty to coiling, at present coiling enamelled wire of multiturn so on less than the bead of 10mm diameter, no matter be machine coiling or manual coiling, all have processing difficulties.Adopt the machine coiling, when ground floor winds, when the second layer, the enamelled wire of the second layer is difficult to be stacked on the ground floor, can destroy the line order of ground floor, and the result is more around poorer, more random; And manual coiling, around the number of turn, entirely remember diligently by the operator, very difficult assurance is seldom around one or two circles, or few around one or two circle, the number of turn is in case change, then deviation just appears in output voltage, after the transformer installation, can not realize original function when serious.
Owing to relate to a large amount of manual coilings, this also is the high reason of micropower power supply module manufacturing cost that causes adopting self-excitation push-pull type translation circuit.
The volume ratio of 2, unsaturation formula self-excited push-pull type transducer transformer is larger
This has description previously described " power conversion technology " the 57th page to 70 pages, from the micropower power supply module of annual nearly 7,000 ten thousand self-excited push-pull type transducers that increase newly of global industrial circle, also can find out, unsaturation formula self-excited push-pull type transducer transformer is not applied owing to volume and following reason.
The reliability of 3, unsaturation formula self-excited push-pull type transducer is relatively poor
This has description at previously described " power conversion technology " the 59th page of the 6th row: " frequency is unstable during visible sort circuit load variations ", its operating frequency changes excessive in underloading and full load.The 5V of contrast industrial circle use amount maximum is to 5V, and the converter of output current 200mA is the saturation type self-excited push-pull type transducer, and its operating frequency is 100KHz or 200KHz, and in fully loaded and unloaded situation, its operating frequency changes generally in 5%.If be designed to unsaturation formula self-excited push-pull type transducer, magnetic core adopts the common magnetic core of ER7.5, and operating frequency is about 2MHz when zero load, and drops to about 300KHz in the full load frequency; So wide frequency range is easy to interfere with miscellaneous equipment, because miscellaneous equipment is difficult to carry out the design of evading for interference source; Even ER7.5 minute surface magnetic core in the employing prior art, operating frequency is about 310KHz when zero load, and drops to about 238KHz in the full load frequency, and its rate of change reaches 29% more than.
At present, comprise that Chinese application number is the self-excited push-pull type transducer of mentioning in 201010604284.7,201110200894.5,201110242377.4,201110247645.1,201110272261.5,201110436259.7 files, all do not have suitable technology to overcome the shortcoming that self-excited push-pull type transducer is described at preamble, be summarized as follows:
1) transformer winding of saturation type self-excited push-pull type transducer difficulty;
The volume ratio of 2) unsaturation formula self-excited push-pull type transducer transformer is larger;
The reliability of 3) unsaturation formula self-excited push-pull type transducer is relatively poor.
Summary of the invention
In view of this, the present invention overcomes above-mentioned deficiency, and a kind of self-excited push-pull type transducer is provided, so that the transformer winding of self-excited push-pull type transducer is convenient, volume is little, and the operating frequency rate of change is in 20%.
The objective of the invention is to be achieved through the following technical solutions:
For solving the problems of the technologies described above, the invention provides a kind of self-excited push-pull type transducer, it is characterized in that: its transformer is that two above magnetic cores combine, the faying face of magnetic flux process is minute surface, adopt magnetic liquid to fill up after the magnetic core combination or after High temperature diffusion processes air gap, part or all disappears so that air gap disappears, thereby realizes the effect of whole magnetic core with Combined type magnetic core.
For solving the problems of the technologies described above, the technical scheme that the first of the present invention is concrete is: a kind of self-excited push-pull type transducer, it is characterized in that: its transformer is that two above magnetic cores combine, and the faying face of magnetic flux process is minute surface, and magnetic core minute surface junction air gap is filled up with magnetic liquid;
Preferably, above-mentioned magnetic liquid is that nano magnetic particle is dispersed in the stable colloidal solutions that forms in the carrier fluid, and the saturation flux density of magnetic liquid is more than 180 Gausses;
More preferably, the saturation flux density of above-mentioned magnetic liquid is more than 2000 Gausses.
For solving the problems of the technologies described above, the concrete technical scheme of the second of the present invention is: a kind of self-excited push-pull type transducer, it is characterized in that: its transformer is that two above magnetic cores combine, and the faying face of magnetic flux process is minute surface, and minute surface combines the adhesion that produces at 4.3N/cm
2More than, after the winding that coiling is good is loaded onto magnetic core, place under the high temperature about the magnetic core Curie temperature and toast, until magnetic core minute surface adhesion is at 7N/cm
2More than.
Operation principle of the present invention is that the self-excited push-pull type transducer of technique scheme, its transformer are that two above magnetic cores combine, like this, just can wind transformer at skeleton, or consist of coil with the Copper Foil cabling on the circuit board, load onto each magnetic core from the circuit board both sides again.The faying face of magnetic flux process is minute surface, minute surface---be the tidemark of metal cutting processing, continued to use this vocabulary on the magnetic core, refer to that the magnetic core surface obtains extraordinary roughness, the clear inverted image of energy goes out the magnetic material surface of article image.When the minute surface magnetic core generally is magnetic core respective surfaces roughness＜0.8um surperficial, be called the minute surface magnetic core, which kind of no matter with processing method process, always stay fine scraggly vestige at the magnetic core finished surface, the staggered peak valley phenomenon that rises and falls occurs, good minute surface combines the adhesion that produces at 7N/cm
2More than, this adhesion comes from the molecular attraction on both sides, minute surface junction, this is the technique upper limit of present minute surface magnetic core, and the existence of molecular attraction illustrates that magnetic domain seldom connects together, because very little, have some magnetic fluxs to exist, this part magnetic domain that connects together will be saturated, and saturated rear this part magnetic domain that connects together and air are as broad as long, realize that this saturated winding current is too little, the transformer of self-excitation push-pull type conversion still is operated in unsaturated state.The minute surface degree is higher, and this gravitation is larger, but the methods such as grinding can't further strengthen this adhesion, and still there is air gap in its faying face, is still scraggly vestige after the amplification, the staggered peak valley phenomenon that rises and falls occurs, thereby produces air gap.Therefore magnetic core can not enter saturation condition, and the magnetic domain on both sides, minute surface junction still is in separately operating state.
The technical scheme that the first of the present invention is concrete is: the faying face of magnetic flux process is minute surface, and magnetic core minute surface junction air gap is filled up with magnetic liquid.Magnetic liquid is that nano magnetic particle is dispersed in the stable colloidal solutions that forms in the carrier fluid, it is a kind of functional material that has simultaneously magnet magnetic and liquid fluidity, filled up minute surface junction air gap with magnetic liquid, nanoscale magnetic material in the magnetic liquid has connected the magnetic domain of air gap both sides, select suitable magnetic liquid, thereby so that the magnetic core after the combination can easily be realized magnetic saturation.
The method that the concrete technical scheme of the second of the present invention is taked: after the winding that coiling is good is loaded onto magnetic core, place under the high temperature about the magnetic core Curie temperature and toast, until magnetic core minute surface adhesion is at 7N/cm
2More than; The lifting of minute surface adhesion is to derive from two molecules between the minute surface again diffusion motion (random motion) at high temperature, and diffusion is so that magnetic domain " growth ", finally is equivalent to the air gap disappearance together.Thereby realize realizing with Combined type magnetic core the effect of whole magnetic core.
From the atomic structure viewpoint of material, the interaction that causes because of spin between the interior electronics of magnet matter is very strong, and under this effect, ferromagnetics inside has formed some small spontaneous magnetization zones, is called magnetic domain.
Place under the above temperature of magnetic core Curie temperature and toast, allow exactly the spontaneous magnetization zone of magnetic domain disappear, acceleration molecular again diffusion motion at high temperature, magnetic core recovers its magnetic characteristic after the cooling, but the minute surface faying face is grown " together, thus realization realizes the effect of whole magnetic core with Combined type magnetic core.
Owing to used two above magnetic cores to combine, the winding part coiling of transformer is simple, after finishing, coiling is loaded on magnetic core, and after magnetic core adopts High temperature diffusion or magnetic liquid to fill up processing, the same performance that realizes using the such self-excited push-pull type transducer of magnet ring, compared with prior art, the present invention has following significant effect:
(1) transformer winding of self-excited push-pull type transducer of the present invention is simple;
Owing to used two above magnetic cores to combine, the winding part coiling of transformer is simple, is loaded on magnetic core after coiling is finished; Or directly design winding at circuit board, and directly load onto magnetic core after processing circuit board, so transformer winding technique is simple, save man-hour;
(2) volume of transformer of self-excited push-pull type transducer of the present invention is smaller;
After combined magnet core adopted High temperature diffusion or magnetic liquid to fill up processing, self-excited push-pull type transducer still can be realized utilizing the magnetic core saturation characteristic to carry out push-pull oscillator, and volume of transformer is little, and efficient is high;
(3) good reliability of self-excited push-pull type transducer of the present invention
For these reasons, self-excited push-pull type transducer still can be realized utilizing the magnetic core saturation characteristic to carry out push-pull oscillator, frequency stabilization, good reliability.
(4) efficient further promotes
Compare with the self-excited push-pull type transducer of the common magnet ring of available technology adopting, efficient can further promote.Combined magnet core adopts magnetic liquid to fill up or after High temperature diffusion processes, the good parameter of reasonable design, its minute surface junction can produce one " thin section ", allowing provides in the magnetic core zone of saturation of recommending energizing signal only to appear at " thin section ", can further improve the operating efficiency of self-excited push-pull type transducer, the relevant detailed operation principle of this part is applied for referring to another part of inventor: Chinese application number is 201110436259.7 " a kind of self-excited push-pull type transducer ".
Description of drawings
Fig. 1 is the common application circuit of self-excited push-pull type transducer Royer circuit;
Fig. 2 is the common application circuit of self-excited push-pull type transducer Jensen circuit;
Fig. 3 is the oscillogram of output of the Royer circuit winding Ns of Fig. 1;
Fig. 4 is the square magnetic hysteresis loop of transformer B1 magnetic core in the Royer circuit of Fig. 1;
If being magnetic core corresponding to Fig. 4, Fig. 5 opens magnetic hysteresis loop and original comparison diagram behind the very little air gap;
The magnet ring type magnetic core that Fig. 6 adopts for existing self-excited push-pull type transducer;
Fig. 7 is the Combined type magnetic core of first, second, third embodiment transformer adopting;
Fig. 8 is for having unsaturation formula self-excited push-pull type transducer now when zero load, the collector current oscillogram;
Fig. 9 be the first embodiment under zero load, actual measurement recommend the transistor collector current waveform;
Figure 10 is the first embodiment fully loaded lower, actual measurement recommend the transistor collector current waveform;
Figure 11 is the Combined type magnetic core schematic diagram of the 4th embodiment house transformer;
Figure 12 is the Combined type magnetic core schematic diagram of the another kind of execution mode house transformer of the 4th embodiment.
Embodiment
Embodiment one
The schematic diagram of the self-excited push-pull type transducer of the first embodiment adopts Fig. 1 circuit, Fig. 7 is the Combined type magnetic core schematic diagram that the first embodiment transformer B1 adopts, adopt comparatively common ER7.5 magnetic core, the magnetic material derives from the TPW33 of TDG Holding Co., Ltd., outward appearance as shown in Figure 7, six faces of 22 indications are minute surfaces.
As shown in Figure 1, the first embodiment makes the converter circuit that 5V becomes 5V output current 250mA, and capacitor C is 2.2uF, capacitor C 1 is 0.33uF, and resistance R 1 is 1.8K Ω, and triode TR1 and TR2 are the S8050 triode, transformer B1 all adopts the circuit board upward wiring to form winding N
P1And N
P2Be respectively 4 circles, feedback winding N
B1And N
B2Be respectively 1 circle, and output winding N
SBe that 10 circle bands are centre tapped, and connect full-wave rectifying circuit on the circuit board, the diode in the full-wave rectifying circuit is BAV70, and filter capacitor is the SMD electric capacity of 1.5uF.
After the above-mentioned device of the self-excited push-pull type transducer of the first embodiment welds, before circuit board is buckled the magnetic core of Fig. 7, on 3 minute surfaces of a magnetic core, drip respectively an amount of magnetic liquid, the model of magnetic liquid is the LD2020 of golden section, and its saturation flux density is about 200 Gausses.
Simultaneously, use homemade magnetic liquid, adopted the magnetic material of high magnetic permeability, behind the sintering, grind into powder, and filter out the following magnetic of 500 orders, loud speaker is with among the magnetic liquid LD2003 preferably to sneak into flowability, and the control mixed volume makes the saturation flux density of mixed magnetic liquid get final product in 2000 Gausses.
Annotate: order refers to the empty eye number on the screen cloth per square inch, and 50 orders just refer to that every square of eyelet on the English inch is 50, and 500 orders are exactly 500, and the order number is higher, and eyelet is more.Except the eyelet of expression screen cloth, it is used for the particle diameter that expression can be passed through the particle of screen cloth simultaneously, and the order number is higher, and particle diameter is less.500 orders of our country refer to 25 microns of particle diameters.The magnet that particle diameter is 25 microns, the magnetic domain of the spontaneous magnetization that is in fact caused by the interior electron spin of a lot of magnet matter forms, and they are subjected to external force can be separated into a plurality of magnetic domains in magnetic liquid and reassemble into a large magnetic domain.
Beneficial effect of the present invention for convenience of description, here having tested three kinds of circuit finishes identical, three kinds of schemes that the magnetic core assembly method is different: the first, prior art, what does not all add in the middle of the ER7.5 magnetic core of Fig. 7, in order to contrast conveniently, still with the first embodiment in the prior art scheme identical; The second, one of first embodiment adopt saturation flux density to fill up the minute surface junction at 200 Gausses' magnetic liquid, the third, two of the first embodiment adopts saturation flux density to fill up the minute surface junction at 2000 Gausses' magnetic liquid.
Test result is referring to table one.
The first, prior art, what does not all add in the middle of the ER7.5 magnetic core of Fig. 7.1147A current probe with Agilent cooperates Agilent DSO-X 3024A digital oscilloscope, the collector current under zero load of triode TR1 or TR2 in the resolution chart 1, waveform according to electric current judges whether transformer saturation type self-excited push-pull type transducer, and method derives from " power conversion technology " book that preamble mentions the 65th page of the 5th paragraph and " 1. observes the collector current waveform with oscilloscope ".The collector current under zero load of triode TR1 or TR2 in the resolution chart 1, Fig. 8 shows the sectional drawing of prior art, and Current rise does not have little point, illustrates that prior art is operated in the self-excitation of unsaturation formula and recommends down.
Fig. 9 shows the test result of the first scheme self-excited push-pull type transducer among the first embodiment, there is little point in electric current, the method of introduction that " power conversion technology " the 65th page of the 5th paragraph " 1. observed the collector current waveform with oscilloscope ", institute's exemplary graph is consistent, have little point, 31 of Fig. 9 is exactly this little point.Illustration is at the upper figure of former book Fig. 2-26 figure (54 pages of former books).The operating frequency of first embodiment the first scheme is 156.41KHz as can be seen from Figure 9; Attention: the electric current of measuring among Fig. 9 has negative current, take triode TR1 as example, this is when triode TR2 saturation conduction, the collector voltage of triode TR1 produces the voltage of one times of supply voltage because of induction, here be 10V, this voltage is to the junction capacitance charging of collector electrode and the emitter of triode TR1, be converted to cut-off and work as triode TR2, triode TR1 is converted to saturation conduction, in this process, the 10V voltage on the collector electrode of triode TR1 and the junction capacitance of emitter is by Transformer Winding N
P1Discharge causes that this is normal phenomenon to power supply Vin (5V), also exists in the upper figure of " power conversion technology " the 54th page of Fig. 2-26 figure.
And when the self-excited push-pull type transducer of first embodiment the first scheme at full load, namely export the 5V direct voltage, output current is 250mA, at this moment records the collector current of triode TR1 or TR2 as shown in figure 10, as can be seen from Figure 10, " power conversion technology " given example is consistent, at figure below (54 pages of former books) of former book Fig. 2-26, its operating frequency is 149.20KHz as can be seen from Figure 11, compare with zero load, changed 4.8%.Realized the object of the invention fully.
The third scheme of the first embodiment, test result are all similar with Fig. 9, Figure 10, are operated in the self-excitation of magnetic core saturation type and recommend down, no longer sectional drawing explanation here.Because operating frequency is reduced to 93.45KHz, the benefit of bringing is the reduction of switching loss, so in the table one, along with the magnetic flux density increase of the magnetic liquid that adopts, operating frequency reduces, and the improved efficiency of self-excitation push-pull converter.Two embodiments among the first embodiment have realized the object of the invention equally.
Embodiment two
The schematic diagram of the self-excited push-pull type transducer of the second embodiment adopts Fig. 1 circuit, Fig. 7 is the Combined type magnetic core schematic diagram that the second embodiment transformer B1 adopts, and adopts comparatively common ER7.5 magnetic core, and the magnetic material still is above-mentioned TPW33, outward appearance as shown in Figure 7, six faces of 22 indications are minute surfaces.
As shown in Figure 1, the second embodiment makes the converter circuit that 5V becomes 5V output current 250mA, and capacitor C is 1uF, capacitor C 1 is 0.22uF, and resistance R 1 is 1.5K Ω, and triode TR1 and TR2 are the S8050 triode, transformer B1 all adopts the circuit board upward wiring to form winding N
P1And N
P2Be respectively 4 circles, feedback winding N
B1And N
B2Be respectively 1 circle, and output winding N
SBe that 10 circle bands are centre tapped, and connect full-wave rectifying circuit on the circuit board, the diode in the full-wave rectifying circuit is BAV70, and filter capacitor is the SMD electric capacity of 2.2uF.
After transformer B1 assembling is finished, place under the high temperature about the magnetic core Curie temperature and toast, the Curie temperature of TPW33 magnetic material is out of shape in order to prevent circuit board greatly about 220 ℃, and device variation on the circuit board, adopts 175 ℃ high temperature here.And clamp magnetic core from the up and down both sides of Fig. 7, in order to magnetic domain again diffusion at high temperature, transformer B1 places together with circuit board in 175 ℃ the insulating box after 2 hours, in order not destroy transformer B1, also put into simultaneously a pair of magnetic core that does not have device, circuit board, be used for contrast and use.The magnetic core minute surface adhesion of actual measurement contrast usefulness rises to 7N/cm
2About; Take out the circuit of packing into after the cooling.
Transformer B1 places in 175 ℃ the insulating box, and the time is longer, and the minute surface adhesion rises more, but rises to 7N/cm
2During the left and right sides, further rise, institute's time spent is long, consume too much electric energy again, and cost performance is not high, determines at 7N/cm at last through test of many times
2During the left and right sides, cost performance is higher, and result of use is better after the installation.
Beneficial effect of the present invention for convenience of description, tested two kinds of two kinds of schemes that circuit is identical, the magnetic core assembly method is different here: the first, prior art, what does not all add in the middle of the ER7.5 magnetic core of Fig. 7; The 4th kind (for distinguish above-mentioned the second, the third), namely the second embodiment adopts above-mentioned High temperature diffusion.
Test result is referring to table two.
The full load efficiency of surveying the second embodiment self-excited push-pull type transducer is 75.6%, uses above-mentioned method of testing, the collector current under zero load of triode TR1 or TR2 in the resolution chart 1.The test result of prior art is referring to Fig. 8, and Current rise does not have little point, illustrates that prior art is operated in the self-excitation of unsaturation formula and recommends down, and the 4th kind, i.e. the second embodiment, and test result is all similar with Fig. 9, Figure 10, and just operating frequency is higher.Here no longer sectional drawing explanation.
Operating frequency is still higher in this example, and this is because in this example, the Curie temperature of high-temperature temperature and magnetic core is compared low, and is low 45 ℃; Be on the other hand: utilize the circuit board cabling to do flat surface transformer, the number of turn is less, if the number of turn doubles, its operating frequency reduces, and conversion efficiency raises the just this application shown in the 3rd embodiment.
Embodiment three
Fig. 1 is the schematic diagram of the 3rd embodiment self-excited push-pull type transducer, and Fig. 7 is the Combined type magnetic core that the 3rd embodiment transformer B1 adopts, and its coiling number of turn is different with the second embodiment with installation method.As shown in Figure 1, the 3rd embodiment makes the converter circuit that 5V becomes 5V output current 250mA, capacitor C is 1uF, capacitor C 1 is 0.22uF, resistance R 1 is 1.5K Ω, and triode TR1 and TR2 are the FMMT491 triode, transformer B1 coiling on skeleton supporting on the ER7.5 magnetic core, adopt the high strength enamelled wire coiling of 180 ℃ of heatproofs, winding N
P1And N
P2Be respectively 8 circles, feedback winding N
B1And N
B2Be respectively 2 circles, and output winding N
SBe that 18 circle bands are centre tapped, and connect full-wave rectifying circuit, the diode in the full-wave rectifying circuit is RB160, and filter capacitor is the SMD electric capacity of 2.2uF.
After transformer B1 assembling was finished, transformer B1 placed under the high temperature about the magnetic core Curie temperature and toasts, and the Curie temperature of TPW33 magnetic material is greatly about 220 ℃, in order to prevent the framework deformation of transformer B1, and the enamelled wire variation, adopt 200 ℃ high temperature here.And clamp Combined type magnetic core from both sides, in order to magnetic domain again diffusion at high temperature, transformer B1 places 200 ℃ insulating box interior after 1 hour, and magnetic core minute surface adhesion rises to 7N/cm
2About; Because temperature is high, the time can shorten, although just 1 hour, actual adhesion is greater than the second embodiment.Take out the circuit of packing into after the cooling.
Beneficial effect of the present invention for convenience of description, test equally two kinds of circuit here and finished two kinds of identical, that the magnetic core assembly method is different schemes: the first, prior art, what does not all add in the middle of the ER7.5 magnetic core of Fig. 7; The 5th kind (above-mentioned several in order to distinguish), namely the 3rd embodiment adopts the High temperature diffusion in above-described embodiment two.
Test result is referring to table three.
The first, prior art, what does not all add in the middle of the ER7.5 magnetic core of Fig. 7, use above-mentioned method of testing, the collector current under zero load of triode TR1 or TR2 in the resolution chart 1, the test result of prior art is referring to Fig. 8, Current rise does not have little point, illustrate that prior art is operated in the self-excitation of unsaturation formula and recommends down, and the 5th kind of scheme, i.e. the 3rd embodiment, test result is all similar with Fig. 9, Figure 10, just operating frequency is lower, is operated in the self-excitation of magnetic core saturation type and recommends down, no longer sectional drawing explanation here.Because operating frequency reduces, the benefit of bringing is in the unit interval, and the number of times of switch reduces, total losses reduce equally, so in the table two, along with the reasonable increase of the number of turn, adopt the more high temperature of asymptotic Curie temperature, operating frequency obviously reduces, and the improved efficiency to 80.4% of self-excitation push-pull converter.Realized the object of the invention.
Embodiment four
The schematic diagram of the self-excited push-pull type transducer of the 3rd embodiment adopts Fig. 1 circuit, Figure 11 is the Combined type magnetic core schematic diagram that the 4th embodiment transformer B1 adopts, adopt comparatively common ER7.5 magnetic core and an I type magnetic core to combine, the magnetic material derives from the TP4G of TDG Holding Co., Ltd., outward appearance as shown in figure 11,4 faces of 22 indications all are minute surfaces.
The parameter of circuit still utilizes the circuit board cabling to do flat surface transformer with the second embodiment, owing to used I type magnetic core, so that the self-excited push-pull type transducer of making at last has more practicality, adopts and carries out High temperature diffusion with embodiment two identical temperature.
Its conversion efficiency is higher than the data in the table two, and operating frequency is a little more than the data in the table two.Use above-mentioned method of testing, there is little point equally in the collector current under zero load of triode TR1 or TR2 in the resolution chart 1, proves that circuit is operated in the self-excitation of magnetic core saturation type and recommends down, and is similar with Fig. 9, Figure 10, no longer sectional drawing explanation here.The 4th embodiment has realized the object of the invention equally.
Obviously, I type magnetic core is changed into two, or other form that changes into of ER7.5, equally can realize the object of the invention.Figure 12 shows this application, and I type magnetic core changes two a little bit smaller I type magnetic cores into, and its downward face is minute surface, and these two can be adopted different magnetic materials, presses the direction of arrow among the figure and following ER magnetic core assembling gets final product, and can realize the object of the invention equally.
Only be preferred implementation of the present invention below, should be pointed out that above-mentioned preferred implementation should not be considered as limitation of the present invention, protection scope of the present invention should be as the criterion with the claim limited range.For those skilled in the art, without departing from the spirit and scope of the present invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (7)
1. a self-excited push-pull type transducer comprises a push-pull transformer, it is characterized in that: the magnetic core of described push-pull transformer is that two above magnetic cores combine, and the faying face of magnetic flux process is minute surface, and described minute surface junction air gap is filled up with magnetic liquid.
2. self-excited push-pull type transducer, comprise a push-pull transformer, it is characterized in that: the magnetic core of described push-pull transformer is that two above magnetic cores combine, and the faying face of magnetic flux process is minute surface, and described minute surface combines the adhesion that produces at 4.3N/cm
2More than, after the winding that coiling is good is loaded onto described magnetic core, place under the high temperature about described magnetic core Curie temperature and toast, until described magnetic core minute surface adhesion is at 7N/cm
2More than.
3. self-excited push-pull type transducer according to claim 1, it is characterized in that: described magnetic liquid is that nano magnetic particle is dispersed in the stable colloidal solutions that forms in the carrier fluid.
4. self-excited push-pull type transducer according to claim 3, it is characterized in that: the saturation flux density of described magnetic liquid is more than 180 Gausses.
5. self-excited push-pull type transducer according to claim 3, it is characterized in that: the saturation flux density of described magnetic liquid is more than 2000 Gausses.
6. self-excited push-pull type transducer according to claim 1 and 2 is characterized in that: wind described transformer at skeleton, and then load onto described magnetic core.
7. self-excited push-pull type transducer according to claim 1 and 2 is characterized in that: consist of coil with the Copper Foil cabling on the circuit board, load onto described magnetic core from described circuit board both sides again.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310003053.4A CN103077806B (en) | 2013-01-04 | A kind of self-excited push-pull type transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310003053.4A CN103077806B (en) | 2013-01-04 | A kind of self-excited push-pull type transducer |
Publications (2)
| Publication Number | Publication Date |
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| CN103077806A true CN103077806A (en) | 2013-05-01 |
| CN103077806B CN103077806B (en) | 2016-11-30 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393769A (en) * | 2014-11-26 | 2015-03-04 | 广州金升阳科技有限公司 | Quasi-soft switching method of Jensen circuit converter and circuit |
| CN109087789A (en) * | 2018-08-27 | 2018-12-25 | 郑州云海信息技术有限公司 | A kind of power inductance and power supply unit |
| WO2021048721A1 (en) * | 2019-09-11 | 2021-03-18 | 3M Innovative Properties Company | Transformer and device configured to provide a current limiting power source and a galvanic barrier |
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| US5204653A (en) * | 1990-01-22 | 1993-04-20 | Tabuchi Electric Co., Ltd. | Electromagnetic induction device with magnetic particles between core segments |
| CN1619722A (en) * | 2003-11-17 | 2005-05-25 | Tdk株式会社 | Transformer core, transformer, and method of production thereof |
| CN101651017A (en) * | 2009-01-14 | 2010-02-17 | 郑州乾新电子有限公司 | Liquid-magnetism filled high-frequency transformer |
| CN201893232U (en) * | 2010-08-04 | 2011-07-06 | 湖北天瑞电子有限公司 | Open type current transformer |
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| US5204653A (en) * | 1990-01-22 | 1993-04-20 | Tabuchi Electric Co., Ltd. | Electromagnetic induction device with magnetic particles between core segments |
| CN1619722A (en) * | 2003-11-17 | 2005-05-25 | Tdk株式会社 | Transformer core, transformer, and method of production thereof |
| CN101651017A (en) * | 2009-01-14 | 2010-02-17 | 郑州乾新电子有限公司 | Liquid-magnetism filled high-frequency transformer |
| CN201893232U (en) * | 2010-08-04 | 2011-07-06 | 湖北天瑞电子有限公司 | Open type current transformer |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104393769A (en) * | 2014-11-26 | 2015-03-04 | 广州金升阳科技有限公司 | Quasi-soft switching method of Jensen circuit converter and circuit |
| CN109087789A (en) * | 2018-08-27 | 2018-12-25 | 郑州云海信息技术有限公司 | A kind of power inductance and power supply unit |
| WO2021048721A1 (en) * | 2019-09-11 | 2021-03-18 | 3M Innovative Properties Company | Transformer and device configured to provide a current limiting power source and a galvanic barrier |
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